APOD: Milky Way over Yellowstone (2020 Jan 29)

[APOD Robot]

Milky Way over Yellowstone

Explanation: The Milky Way was not created by an evaporating lake. The pool of vivid blue water, about 10 meters across, is known as Silex Spring and is located in Yellowstone National Park in Wyoming, USA. Steam rises off the spring, heated by a magma chamber deep underneath known as the Yellowstone hotspot. The steam blurs the image of Jupiter, making it seem unusually large. Unrelated and far in the distance, the central band of our Milky Way Galaxy rises high overhead, a band lit by billions of stars. The featured picture is a 3-image panorama taken last August. If the Yellowstone hotspot causes another supervolcanic eruption as it did 640,000 years ago, a large part of North America would be affected.

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[Guest]

Uh, Venus? How about Jupiter?

[Ann]

I was unable to even open the APOD page. Does anyone else have that problem?

Ann

[Ann]

Okay, now I was able to open the APOD page!

I guess that today's APOD, even though it is a 3-image panorama, is not a composite using different exposure times for the sky and for the ground. I base my guess on the rather colorless appearance of the Milky Way, which suggests to me that this photograph was taken in a relatively "straightforward" way, possibly with no exposures through different filters.

We see no "drifting" of the sky, which I guess means that the camera was following the apparent "westward drift" of the sky. But we also see no sign that the sky and the ground are not stationary relatively to each other. Are we talking short exposures here? Is that possible, given the faintness of the Milky Way?

I am of course fascinated by the very blue color of the water in the pool, and the even bluer color of the steam rising out of it. What causes it?

Ann

[dipi]

I seem to have a problem with the TLS certificate of the APOD site.
There’s a http-to-https redirect, so I’m not even able to retrieve the unencrypted version.

[orin stepanek]

We went there when the kids were little! It is a very interesting place; and worth visiting. We weren't looking at the Milky Way however!

[neufer]

<<I am of course fascinated by the very blue color of the water in the pool, and
the even bluer color of the steam rising out of it. What causes it?>>

Purity Of Essence

General Buck Turgidson (George C. Scott): "So let's get going, there's no other choice. God willing, we will prevail, in peace and freedom from fear, and in true health, through the purity and essence of our natural... fluids. God bless you all." And [then Brigadier General Jack D. Ripper (Sterling Hayden)] hung up. [Pause as he realizes the implications of General Ripper's words] Uh, we're... still trying to figure out the meaning of that last phrase, sir.

<<While relatively small quantities of water appear to be colorless, pure water has a slight blue color that becomes a deeper blue as the thickness of the observed sample increases. The blue hue of water is an intrinsic property and is caused by selective absorption and scattering of white light.

The water molecule has three fundamental modes of vibration.

---

The water molecule has three fundamental modes of vibration. Two stretching vibrations of the O-H bonds in the gaseous state of water occur at [infrared frequencies:] v₁ = 3650 cm⁻¹ and v₃ = 3755 cm⁻¹. Absorption due to these vibrations occurs in the infrared region of the spectrum. The absorption in the visible spectrum is due mainly to the harmonic v₁ + 3v₃ = 14,318 cm⁻¹, which is equivalent to a wavelength of 698 nm. In liquid state at 20°C these vibrations are red-shifted due to hydrogen bonding, resulting in red absorption at 740 nm, other harmonics such as v₁ + 3v₃ giving red absorption at 660 nm.

The intrinsic colour of liquid water may be demonstrated by looking at a white light source through a long pipe that is filled with purified water and closed at both ends with a transparent window. The light turquoise blue colour is caused by weak absorption in the red part of the visible spectrum. Absorption intensity decreases markedly with each successive overtone, resulting in very weak absorption for the third overtone. For this reason, the pipe needs to have a length of a meter or more and the water must be purified by microfiltration to remove any particles that could produce Mie scattering.>>

The Grand Prismatic Spring

---

<<The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States, and the third largest in the world, after Frying Pan Lake in New Zealand and Boiling Lake in Dominica. Its colors match most of those seen in the rainbow dispersion of white light by an optical prism: red, orange, yellow, green, and blue.

The vivid colors in the spring are the result of microbial mats around the edges of the mineral-rich water. The mats produce colors ranging from green to red; the amount of color in the microbial mats depends on the ratio of chlorophyll to carotenoids and on the temperature gradient in the runoff. In the summer, the mats tend to be orange and red, whereas in the winter the mats are usually dark green.

The center of the pool is sterile due to extreme heat. The deep blue color of the water in the center of the pool results from the intrinsic blue color of water. The effect is strongest in the center of the spring, because of its sterility and depth. The spring is approximately 110 m in diameter and is 50 m deep.>>

Milky Way over Yellowstone (2014 August 27)

Explanation: The Milky Way was not created by an evaporating lake. The colorful pool of water, about 10 meters across, is known as Silex Spring and is located in Yellowstone National Park in Wyoming, USA. Illuminated artificially, the colors are caused by layers of bacteria that grow in the hot spring. Steam rises off the spring, heated by a magma chamber deep underneath known as the Yellowstone hotspot. Unrelated and far in the distance, the central band of our Milky Way Galaxy arches high overhead, a band lit by billions of stars. The above picture is a 16-image panorama taken late last month. If the Yellowstone hotspot causes another supervolcanic eruption as it did 640,000 years ago, a large part of North America would be affected.

[neufer]

Tralfamadore

---

We went there when the kids were little!

It is a very interesting place; and worth visiting.

All are welcome

[wenbin]

great!

[Ann]

General Buck Turgidson (George C. Scott): "So let's get going, there's no other choice. God willing, we will prevail, in peace and freedom from fear, and in true health, through the purity and essence of our natural... fluids. God bless you all." And [then Brigadier General Jack D. Ripper (Sterling Hayden)] hung up. [Pause as he realizes the implications of General Ripper's words] Uh, we're... still trying to figure out the meaning of that last phrase, sir.

Click to view full size image

Brigadier General Jack D. Strangelove Ripper????

<<While relatively small quantities of water appear to be colorless, pure water has a slight blue color that becomes a deeper blue as the thickness of the observed sample increases. The blue hue of water is an intrinsic property and is caused by selective absorption and scattering of white light.

The water molecule has three fundamental modes of vibration.

---

The water molecule has three fundamental modes of vibration. Two stretching vibrations of the O-H bonds in the gaseous state of water occur at [infrared frequencies:] v₁ = 3650 cm⁻¹ and v₃ = 3755 cm⁻¹. Absorption due to these vibrations occurs in the infrared region of the spectrum. The absorption in the visible spectrum is due mainly to the harmonic v₁ + 3v₃ = 14,318 cm⁻¹, which is equivalent to a wavelength of 698 nm. In liquid state at 20°C these vibrations are red-shifted due to hydrogen bonding, resulting in red absorption at 740 nm, other harmonics such as v₁ + 3v₃ giving red absorption at 660 nm.

The intrinsic colour of liquid water may be demonstrated by looking at a white light source through a long pipe that is filled with purified water and closed at both ends with a transparent window. The light turquoise blue colour is caused by weak absorption in the red part of the visible spectrum. Absorption intensity decreases markedly with each successive overtone, resulting in very weak absorption for the third overtone. For this reason, the pipe needs to have a length of a meter or more and the water must be purified by microfiltration to remove any particles that could produce Mie scattering.>>

The Grand Prismatic Spring

---

<<The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States, and the third largest in the world, after Frying Pan Lake in New Zealand and Boiling Lake in Dominica. Its colors match most of those seen in the rainbow dispersion of white light by an optical prism: red, orange, yellow, green, and blue.

The vivid colors in the spring are the result of microbial mats around the edges of the mineral-rich water. The mats produce colors ranging from green to red; the amount of color in the microbial mats depends on the ratio of chlorophyll to carotenoids and on the temperature gradient in the runoff. In the summer, the mats tend to be orange and red, whereas in the winter the mats are usually dark green.

The center of the pool is sterile due to extreme heat. The deep blue color of the water in the center of the pool results from the intrinsic blue color of water. The effect is strongest in the center of the spring, because of its sterility and depth. The spring is approximately 110 m in diameter and is 50 m deep.>>

Milky Way over Yellowstone (2014 August 27)

Explanation: The Milky Way was not created by an evaporating lake. The colorful pool of water, about 10 meters across, is known as Silex Spring and is located in Yellowstone National Park in Wyoming, USA. Illuminated artificially, the colors are caused by layers of bacteria that grow in the hot spring. Steam rises off the spring, heated by a magma chamber deep underneath known as the Yellowstone hotspot. Unrelated and far in the distance, the central band of our Milky Way Galaxy arches high overhead, a band lit by billions of stars. The above picture is a 16-image panorama taken late last month. If the Yellowstone hotspot causes another supervolcanic eruption as it did 640,000 years ago, a large part of North America would be affected.

Thanks, Art, that's so interesting! Note , however, that in that other APOD, the steam rising from the pool is not blue.

[neufer]

Thanks, Art, that's so interesting! Note , however, that in that other APOD, the steam rising from the pool is not blue.

"Illuminated artificially."

Steam color is Mie scattering of whatever the illumination color was.

Perhaps, the artificial steam illumination in today's APOD was bluer and/or made bluer by being directed into the pool itself.

[Cousin Ricky]

I was unable to even open the APOD page. Does anyone else have that problem?

I cannot connect either. But the image is posted on their Facebook page.

[Ann]

Thanks, Art, that's so interesting! Note , however, that in that other APOD, the steam rising from the pool is not blue.

"Illuminated artificially."

Steam color is Mie scattering of whatever the illumination color was.

Perhaps, the artificial steam illumination in today's APOD was bluer and/or made bluer by being directed into the pool itself.

It was the steam in the APOD of August 27, 2014, that was artificially illuminated!

Nothing is said in the caption of today's APOD that the steam was artificially illuminated.

You mean that the artificial illumination in today's APOD is so obvious that it goes without saying?

Ann

[neufer]

Nothing is said in the caption of today's APOD that the steam was artificially illuminated.

You mean that the artificial illumination in today's APOD is so obvious that it goes without saying?

• That's Mie Artificial illumination on the issue.

[Guest]

Hey,
that should be Jupiter instead of Venus, no?

Dom
Belgium

[Ann]

Nothing is said in the caption of today's APOD that the steam was artificially illuminated.

You mean that the artificial illumination in today's APOD is so obvious that it goes without saying?

• That's Mie Artificial illumination on the issue.

Click to view full size image

Daughter: "Dad, why is the sky blue?"
Dad: "It's the artificial Rayleigh scattering!"

[RJN]

Uh, Venus? How about Jupiter?

Yes, the planet is Jupiter. My bad. This has now been fixed on the main NASA APOD. Apologies. - RJN

[Deathfleer]

Very beautiful. The universe is very very big. SubhanaLlah.

[ta152h0]

Out of curiosity, do vacuum tubes work in space without the glass enclosure? I just broke a 5u4 but didn't scratch the insides.

[neufer]

Out of curiosity, do vacuum tubes work in space without the glass enclosure? I just broke a 5u4 but didn't scratch the insides.

Why would most vacuum tubes care about how large their "glass enclosures" were?

[Chris Peterson]

Out of curiosity, do vacuum tubes work in space without the glass enclosure? I just broke a 5u4 but didn't scratch the insides.

The tubes themselves would work. The circuits they are part of would generally not (or not as intended), as the glass enclosure doesn't just maintain a vacuum around the elements, but it also acts as an insulator to prevent current from flowing between elements of different tubes or other parts of the circuit.

[ta152h0]

so throw away the 5u4, right?!

[Chris Peterson]

so throw away the 5u4, right?!

Replace it with a solid state device. Tubes have almost no place in modern electronics.

[neufer]

---

so throw away the 5u4, right?!

Replace it with a solid state device. Tubes have almost no place in modern electronics.

At least, lug that tube down to your local defunct drugstore (e.g., Peoples, Adams, Happy Harry's, Eckerd, Hook's, Big B, G.O. Guy, Gray, Brooks, Revco, K&B, etc.) and test that sucker